The QPair class is a template class that stores a pair of items. 更多...
| 头： | #include <QPair> |
| typedef | first_type |
| typedef | second_type |
| QPair () | |
| QPair (const T1 & value1 , const T2 & value2 ) | |
| QPair<T1, T2> & | operator= (const QPair<T1, T2> & other ) |
| T1 | first |
| T2 | second |
| QPair<T1, T2> | qMakePair (const T1 & value1 , const T2 & value2 ) |
| bool | operator!= (const QPair<T1, T2> & p1 , const QPair<T1, T2> & p2 ) |
| bool | operator< (const QPair<T1, T2> & p1 , const QPair<T1, T2> & p2 ) |
| QDataStream & | operator<< (QDataStream & out , const QPair<T1, T2> & pair ) |
| bool | operator<= (const QPair<T1, T2> & p1 , const QPair<T1, T2> & p2 ) |
| bool | operator== (const QPair<T1, T2> & p1 , const QPair<T1, T2> & p2 ) |
| bool | operator> (const QPair<T1, T2> & p1 , const QPair<T1, T2> & p2 ) |
| bool | operator>= (const QPair<T1, T2> & p1 , const QPair<T1, T2> & p2 ) |
| QDataStream & | operator>> (QDataStream & in , QPair<T1, T2> & pair ) |
The QPair class is a template class that stores a pair of items.
QPair
<T1, T2> can be used in your application if the STL
pair
type is not available. It stores one value of type T1 and one value of type T2. It can be used as a return value for a function that needs to return two values, or as the value type of a
generic container
.
Here's an example of a
QPair
that stores one
QString
and one
double
值：
QPair<QString, double> pair;
The components are accessible as public data members called first and second 。例如：
pair.first = "pi"; pair.second = 3.14159265358979323846;
QPair 's template data types (T1 and T2) must be 可赋值数据类型 。例如，无法存储 QWidget 作为值；取而代之，存储 QWidget *. A few functions have additional requirements; these requirements are documented on a per-function basis.
另请参阅 容器类 .
The type of the first element in the pair (T1).
另请参阅 first .
The type of the second element in the pair (T2).
另请参阅 second .
Constructs an empty pair. The
第一
and
second
elements are initialized with
default-constructed values
.
Constructs a pair and initializes the
第一
element with
value1
和
second
element with
value2
.
另请参阅 qMakePair ().
赋值 other to this pair.
The first element in the pair.
The second element in the pair.
返回 QPair <T1, T2> that contains value1 and value2 。范例：
QList<QPair<int, double> > list; list.append(qMakePair(66, 3.14159));
这相当于 QPair <T1, T2>( value1 , value2 ), but usually requires less typing.
返回 true 若
p1
不等于
p2
; otherwise returns false. Two pairs compare as not equal if their
第一
data members are not equal or if their
second
data members are not equal.
This function requires the T1 and T2 types to have an implementation of
operator==()
.
返回 true 若
p1
小于
p2
; otherwise returns false. The comparison is done on the
第一
members of
p1
and
p2
; if they compare equal, the
second
members are compared to break the tie.
This function requires the T1 and T2 types to have an implementation of
operator<()
.
Writes the pair pair 到流 out .
This function requires the T1 and T2 types to implement
operator<<()
.
另请参阅 序列化 Qt 数据类型 .
返回 true 若
p1
<=
p2
; otherwise returns false. The comparison is done on the
第一
members of
p1
and
p2
; if they compare equal, the
second
members are compared to break the tie.
This function requires the T1 and T2 types to have an implementation of
operator<()
.
返回 true 若
p1
等于
p2
; otherwise returns false. Two pairs compare equal if their
第一
data members compare equal and if their
second
data members compare equal.
This function requires the T1 and T2 types to have an implementation of
operator==()
.
返回 true 若
p1
大于
p2
; otherwise returns false. The comparison is done on the
第一
members of
p1
and
p2
; if they compare equal, the
second
members are compared to break the tie.
This function requires the T1 and T2 types to have an implementation of
operator<()
.
返回 true 若
p1
>=
p2
; otherwise returns false. The comparison is done on the
第一
members of
p1
and
p2
; if they compare equal, the
second
members are compared to break the tie.
This function requires the T1 and T2 types to have an implementation of
operator<()
.
Reads a pair from stream in into pair .
This function requires the T1 and T2 types to implement
operator>>()
.
另请参阅 序列化 Qt 数据类型 .
